The invention relates to a clamping device for a longitudinally adjustable and/or height-adjustable steering column of a vehicle.
The steering column in a vehicle usually couples a steering wheel to a steering linkage of steerable vehicle wheels such that the vehicle wheels execute a steering movement when the steering wheel is rotated. To allow the steering wheel position to be individually adapted to the wishes and requirements of a particular driver, the steering column is increasingly configured to be adjustable with respect to its length and/or height (or inclination). As soon as the desired steering wheel position is reached, the steering column is fixed in place again such that in driving operation of the vehicle, it then only permits rotation of a steering shaft in relation to a longitudinal axis of the steering column in order to convert a steering wheel rotation into corresponding steering movements of the steerable wheels.
In this connection, clamping devices having a device part and an actuating part are already known from the prior art, the actuating part being movable relative to the device part between a release position, in which the steering column is longitudinally adjustable and/or height-adjustable, and a fixing position, in which the steering column is neither longitudinally adjustable nor height-adjustable. Such a generic clamping device for an adjustable steering column is described in US 2003/0221505 A1, for example.
After releasing the actuating part from its fixing position, the actuating part is urged towards the release position by a spring force and is accelerated. Unless the actuating part is manually guided and braked during its movement from the fixing position to the release position, the spring force results in a kinetic energy of the actuating part, which is abruptly dissipated in the release position, accompanied by the generation of an undesirable, high noise impulse.